By ANAHAD O'CONNOR

Published: September 15, 2005

The mother of a 7-year-old boy who was killed on a boat ride at Playland Amusement Park in August notified Westchester County on Wednesday that she planned to file a lawsuit claiming that the ride at the county-owned park was unsafe and that her son should never have been allowed on it alone.

In her first interview with reporters since her son's death on Aug. 3, Elayne Cassara, 38, lashed out at the park, in Rye, for not posting signs warning that the ride, Ye Old Mill, went through a dark tunnel and could be frightening to small children. She said she believed that her son, Jon-Kely, 7, panicked and climbed out of the boat as it entered the tunnel, and then became stuck between two underwater conveyor belts.

''My son was afraid of the dark,'' Mrs. Cassara said. ''I would never have allowed him to get on a ride by himself if I knew there would be danger. I'm not an irresponsible person.''

Mrs. Cassara, a pastor at a church in Darien, Conn., spoke at a news conference organized by her lawyers outside the county courthouse here.

''Our first and most important concern is that this never ever happens again in this country,'' she said, clutching a red Bible. ''It is a tragedy that a child would embark upon a day that's supposed to be fun but never come home again because of this park's negligence.''

The lawsuit will charge negligence, carelessness and wrongful death, to compel the park to strengthen its safety procedures, Mrs. Cassara said. The suit also seeks an unspecified amount of money.

The death was the second in two years at the popular park on Long Island Sound. In May of last year, another 7-year-old, Stephanie Dieudonn?f New Rochelle, N.Y., was killed after she wiggled out of the metal restraint on an enclosed ride called the Mind Scrambler; she was crushed to death before the operator noticed. Although the park was cleared of any wrongdoing by the state, the girl's family filed a lawsuit against the county in February.

In the weeks after Jon-Kely's death, investigators with the State Department of Labor examined Ye Old Mill and said that the park had not violated any safety procedures but that the ride could be made safer. The state ordered the park to make several improvements, including placing a cover over a 14-inch gap between the two conveyor belts where Jon-Kely's body was found and ensuring that there are always at least four operators on duty at all times, as the county's guidelines require. At the time of the incident, only two attendants were present, investigators said.

''This was a horrible and tragic accident, but Playland was not negligent,'' said Susan Tolchin, a spokeswoman for the county executive's office. ''The state labor department inspected and approved the ride this year as it has done in previous years, and there were no violations.''

Mrs. Cassara said the park could have done a number of things that would have prevented her son's death. She said the park should have equipped the boat with seat belts, posted warning signs that it went through a dark tunnel and provided better supervision.

Mrs. Cassara said she arrived at the park that day around noon with Jon-Kely and his 4-year-old sister, Jaelle. About 4 p.m., the boy got on the ride, a six-minute trip. Mrs. Cassara said she wanted to get on with him but did not have enough points left on her ride card.

When Jon-Kely did not emerge at the end of the tunnel, Mrs. Cassara said, she ran to an attendant and pleaded with him to stop the ride, fearing her son had been kidnapped. The operator refused, she said, and she went to several people standing in line for help in finding her son.

About 20 minutes passed before the ride was stopped. Park officials then drained the ride and discovered the boy's body underwater. A coroner later determined that he died of blunt force trauma to the head.

Mrs. Cassara said she planned to use any money won in the lawsuit to create a private Christian school for underprivileged children, named in her son's honor.

Photo: Elayne Cassara, whose 7-year-old son, Jon-Kely, died on a ride. (Photo by Alan Zale for The New York Times)